Kevin Anderson lost in the first round in Cincinnati on Tuesday night. Photo: Paul Chiasson, The Canadian Press via AP

South Africa’s Kevin Anderson was unable to continue his good run of form of the last few weeks as he was knocked out of the Cincinnati Open on Tuesday night.

The big-serving right-hander smashed 24 aces, but it was still not enough to win as he was beaten by Aleksandr Dolgopolov of Ukraine, who clinched the first-round victory 6-4 7-6(6).

Anderson had reached the quarter-finals of the Rogers Cup Masters 1000 event in Montreal last week, where he was knocked out by German star Alexander Zverev.

Dolgopolov will now take on Nick Kyrgios in the second round.

Australian Kyrgios and Juan Martin del Potro took positive steps in their US Open preparation by ousting seeded opponents to reach the second round.

Former US Open champion del Potro beat 10th-seeded Czech Tomas Berdych 3-6 7-6(1) 6-0, while Kyrgios opened with a 6-2 6-3 dismissal of ninth seed David Goffin of Belgium in the Cincinnati heat.

Earlier in the day, sixth-seeded Canadian Milos Raonic announced his withdrawal from the tournament due to a lingering left wrist injury.

The talented non-seeded winners, who have both battled injuries this season, excelled on serve.

Del Potro powered in 17 aces in overcoming Berdych after a listless opening set.

The Argentine, who was last week ousted in the second round in Montreal by Canadian teenager Denis Shapovalov, upped the aggression in the second set and found his range with his big forehand to force a tiebreak.

Australian star Nick Kyrgios is gearing up for the US Open. Photo: Eric Bolte, USA TODAY SPORTS

He raced to a 5-0 lead in the tiebreak, which he claimed 7-1 before blanking Berdych in the third set.

“I think I played really good tennis in the second and the third set. I think my game improved after a big effort in the second set,” Del Potro told the Tennis Channel.

“I think I can be better, can play much better. I’m having a tougher draw in all tournaments, but I like just to play tennis after all my injuries, and I’m so happy to have the chance.”

Del Potro, who has a history of wrist problems and had a groin injury this season, next plays American qualifier Mitchell Krueger.

Kyrgios cracked 10 aces in a one-sided victory over Goffin.

“He doesn’t have the biggest of weapons and I kind of caught a good rhythm against him,” said the 22-year-old Australian, who retired from three tournaments in a row with hip and shoulder injuries this season.

“He’s by far better than me from the back of the court. He loves playing from the ground, so I tried not to give him much rhythm. I just hit two first serves every point, pretty much.”

Asked about his hip injury, Kyrgios said: “I can still feel it. It’s always tough to play and try to build some strength.”

Reuters, Staff Writer